Based on preclinical data (see preliminary studies) we hypothesize that prostate targeted antisense retroviral vectors may be effective agents in the treatment of metastatic prostate cancer. The study is designed to test this hypothesis and specifically provide information on the following aspects of this therapy. 1) Is there effective uptake and expression of retroviral vector into malignant prostate cancer cells? 2) Is the prostate-targeted retroviral vector specifically expressed within prostate cancer cells or do other cells express the MMTV- based transcription unit in an unexpected fashion? 3) Is there toxicity associated with injection of viral vector in patients with metastatic prostate cancer? 4) Is there an effective reduction in the number of malignant cells following retroviral vector-based injection therapy of carcinomatous prostate?